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What is the purpose of setting a key in data.table?
...operations, setkey() was never an absolute requirement. That is, we can perform a cold-by or adhoc-by.
## "cold" by
require(data.table)
DT <- data.table(x=rep(1:5, each=2), y=1:10)
DT[, mean(y), by=x] # no key is set, order of groups preserved in result
However, prior to v1.9.6, joins of the ...
What are the differences between JSON and JSONP?
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MariusMarius
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psql: FATAL: Ident authentication failed for user “postgres”
...d because there is a security issue, see here: serverfault.com/questions/110154/…
– Erdinc Ay
Jul 12 '16 at 19:52
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Check if all elements in a list are identical
...trix :-).
– mgilson
Oct 6 '16 at 21:01
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How to convert currentTimeMillis to a date in Java?
... nbro
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answered Jun 12 '14 at 11:05
Faisal AshrafFaisal Ashraf
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(Mac) -bash: __git_ps1: command not found
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MBlanc
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answered Oct 13 '12 at 7:47
Mark LongairMark Longair
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How to insert an element after another element in JavaScript without using a library?
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As of 2018, browser support looks pretty solid: caniuse.com/#feat=insert-adjacent
– madannes
May 30 '18 at 14:26
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WebSockets protocol vs HTTP
...on handshakes, but with a WebSocket connection the initial handshake is performed once and then small messages only have 6 bytes of overhead (2 for the header and 4 for the mask value). The latency overhead is not so much from the size of the headers, but from the logic to parse/handle/store those h...
Modify/view static variables while debugging in Eclipse
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edited May 17 '17 at 17:01
Nathan
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answered Apr...
Downloading a file from spring controllers
...r the file.
– GaryF
Apr 15 '11 at 7:01
2
Yep, just edited the post. I had various file types gene...